<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title></title>
    <style>
        div {
            width: 500px;
            height: 100px;
            border: 1px dotted #f00;
        }
    </style>
</head>
<body>
<!--
    IE6不支持一像素的点划线，用背景图代替
-->
<div></div>
</body>
</html>
